The space between fertiliser stacks and walls for should be about

The space between fertilizer stacks and walls should be about 0.75 m.
Storage of the fertilizers is advised to be in the shed, and place the wooden platforms on the pallets, just to avoid contact between the fertilizer sacks and the ground.
The stacks should not exceed 20 bags to avoid shrinking the bags at the bottom.
Leave space of about 60 cm between the stacks.